Parallel determination of NeuroD1, Chromogranin-A, KI67 and androgen receptor expression in surgically treated prostate cancers

PURPOSE: Neuroendocrine differentiation is a hallmark of prostate cancer. The aim of our study was the detection of the parallel expression of neuroendocrine related markers using a prostate tissue microarray (TMA). MATERIALS AND METHODS: Our study was aimed at detecting the parallel expression of NeuroD1, Chromogranin-A (ChrA), Androgen Receptor (AR) and Ki-67 by immunohistochemistry on prostate cancer tissue microarray. The data was analyzed using SAS version 8.2 (SAS Inc, Cary, NC). The relationships between NeuroD1, ChrA and AR expressions and patients' characteristics were investigated by multivariate logistic regression analysis. Progression and Overall Survival (OS) distributions were calculated using Kaplan-Meier method. RESULTS: Tissue reactivity for NeuroD1, ChrA and AR concerned 73 percent, 49 percent and 77 percent of the available cases, respectively. Regarding overall survival, there were 87 deaths and 295 patients alive/censored (6 years of median follow-up). Seventy-seven disease progressions occurred at the median follow-up 5.4y. A significant correlation between NeuroD1, ChrA and AR expression was observed (p < 0.001 and p < 0.03, respectively). Additionally, ChrA was strongly associated in multivariate analysis to Gleason score and Ki67 expression (p < 0.009 and p < 0.0052, respectively). Survival analysis showed no association between markers neither for overall nor for cancer-specific survival. CONCLUSIONS: The results highlight that NeuroD1, Chromogranin-A and Androgen Receptor are strongly associated, however their expression does not correlate with overall survival or disease progression.